BACKGROUND: Cervicitis is one of the major health problems amongst women caused by infection of various pathogens including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) as well as human papillomavirus (HPV), and persistent cervical inflammation is one of the etiologic agents of cervical cancer. Toll-like receptors (TLRs) play an important role in the recognition and subsequent elimination of these pathogens. Variations in the Toll-like receptor genes influence susceptibility to pathogens as well as disease progression independently. METHODS: Ten single nucleotide polymorphisms, five each of TLR4 and TLR9 genes were analyzed among 130 cervicitis patients and 150 controls either using polymerase chain reaction-restriction fragment length polymorphism or allele specific-PCR. RESULTS: T. vaginalis infection was found at the highest frequency (30.7%) as compared to C. trachomatis (1.5%), N. gonorrhoeae (2.3%) and HPV (4.6%) infections in cervicitis patients. TLR4 rs11536889 CC (age-adjusted OR, 2.469 [95% CI, 1.499 to 4.065]; p < 0.001) and TLR9 rs187084 TC (age-adjusted OR, 2.165 [95% CI, 1.267-3.699]; p = 0.005) genotypes showed the higher distribution in cervicitis patients compared to controls. In addition, TLR4 rs11536889 C allele was shown to increase the risk of cervicitis (age-adjusted OR, 1.632 [95% CI, 1.132 to 2.352]; p = 0.009) compared to controls. The TLR4 haplotype GCA (OR, 0.6 [95% CI, 0.38-0.95]; p = 0.0272) and TLR9 haplotype GTA (OR, 1.99 [95% CI, 1.14-3.48]; p = 0.014) were found to be associated with decreased and increased risk of cervicitis respectively. CONCLUSIONS: TLR4 and TLR9 polymorphisms, as well as haplotypes were shown to modulate the cervicitis risk.

Single nucleotide polymorphisms (SNPs) in TLR genes may serve as a crucial marker for early susceptibility of various cancers including cervical cancer. The present study was therefore designed to ascertain the role of TLR4 and TLR9 SNPs and haplotypes to hrHPV infection and cervical cancer susceptibility. The study included 110 cervical cancer biopsies and 141 cervical smears from age-matched healthy controls of Gujarati ethnicity of Western India. hrHPV 16 and 18 were detected using Real-time PCR. Eight SNPs, four each in TLR4 and TLR9 were analyzed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism and Allele-Specific PCR. HPV 16 and 18 were detected in 68% cervical cancer cases. TLR4 rs4986790, rs1927911 and TLR9 rs187084 showed association with HPV 16/18 infection. CC and CT genotypes of TLR4 rs11536889 and rs1927911 respectively, and TC, CC genotypes of TLR9 rs187084, as well as minor alleles of TLR4 rs4986790 and TLR9 rs187084, were associated with the increased risk of cervical cancer. Stage-wise analysis revealed TLR9 rs187084 and rs352140 to be associated with early-stage cancer. TLR4 haplotype GTAC and TLR9 haplotype GATC were associated with the increased risk of cervical cancer while TLR4 haplotype GCAG was associated with the decreased risk. TLR4 haplotype GCAG and TLR9 haplotype GATC showed association with increased susceptibility to hrHPV infection. In conclusion, the present study revealed association of TLR4 and TLR9 polymorphisms and haplotypes with hrHPV infection and cervical cancer risk. Further evaluation of a larger sample size covering diverse ethnic populations globally is warranted.